Segment, Customer Concentration and Geographical Information - Company's Customers that Represent 10% or More of Company's Net Revenues (Detail) - Revenues [Member] - Customer Concentration Risk [Member]	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Wireless [Member] | Sprint and Affiliates [Member]
Revenue, Major Customer [Line Items]
Customer concentrating on 10% or more of net revenue	58.80%	64.50%	60.00%	64.70%
Graphics [Member] | FastSpring [Member]
Revenue, Major Customer [Line Items]
Customer concentrating on 10% or more of net revenue	12.60%	13.70%	14.10%	12.80%